Myosin heavy chain composition of muscle spindles in human biceps brachii
2002 (English)In: Histochem Cell Biol, Vol. 50, no 2, 171-184 p.Article in journal (Refereed) Published
Data on the myosin heavy chain (MyHC) composition of human muscle spindles are scarce in spite of the well-known correlation between MyHC composition and functional properties of skeletal muscle fibers. The MyHC composition of intrafusal fibers from 36 spindles of human biceps brachii muscle was studied in detail by immunocytochemistry with a large battery of antibodies. The MyHC content of isolated muscle spindles was assessed with SDS-PAGE and immunoblots. Four major MyHC isoforms (MyHCI, IIa, embryonic, and intrafusal) were detected with SDS-PAGE. Immunocytochemistry revealed very complex staining patterns for each intrafusal fiber type. The bag(1) fibers contained slow tonic MyHC along their entire fiber length and MyHCI, alpha-cardiac, embryonic, and fetal isoforms along a variable part of their length. The bag(2) fibers contained MyHC slow tonic, I, alpha-cardiac, embryonic, and fetal isoforms with regional variations. Chain fibers contained MyHCIIa, embryonic, and fetal isoforms throughout the fiber, and MyHCIIx at least in the juxtaequatorial region. Virtually each muscle spindle had a different allotment of numbers of bag(1), bag(2) and chain fibers. Taken together, the complexity in intrafusal fiber content and MyHC composition observed indicate that each muscle spindle in the human biceps has a unique identity.
Place, publisher, year, edition, pages
2002. Vol. 50, no 2, 171-184 p.
human biceps brachii, muscle spindles, intrafusal fiber, bag1 fiber, bag 2 fiber, chain fiber, MyHC
Medical and Health Sciences Ophthalmology Cell and Molecular Biology
Research subject Human Anatomy; Ophtalmology
IdentifiersURN: urn:nbn:se:umu:diva-4212PubMedID: 11799136Local ID: 744OAI: oai:DiVA.org:umu-4212DiVA: diva2:143214